Data-flow models  Show processing steps as data flow through system

Data-flow models Show processing steps as data flow through system Show end-to-end processing of data Intuitive notation that clients can understand Developed by DeMarco for Structured Analysis, adopted by and to other analysis methods Ian Sommerville 1995 Software Engineering, 5th edition. Chapter 6 Slide 1

Data-flow diagrams Can show processing at different levels of abstraction from fairly abstract to fairly detailed. Slide 4 is a decomposition of the bolded bubble in slide 3. Can show data interchange between sub-systems, for architectural description. See slide 5. Ian Sommerville 1995 Software Engineering, 5th edition. Chapter 6 Slide 2

DFD: Equipment procurement Ian Sommerville 1995 Software Engineering, 5th edition. Chapter 6 Slide 3

DFD: Place Equipment Order Ian Sommerville 1995 Software Engineering, 5th edition. Chapter 6 Slide 4

CASE toolset DFD Ian Sommerville 1995 Software Engineering, 5th edition. Chapter 6 Slide 5